encode_video.c
/*
* copyright (c) 2001 Fabrice Bellard
*
* This file is part of Libav.
*
* Libav is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* Libav is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
static void encode(AVCodecContext *enc_ctx, AVFrame *frame, AVPacket *pkt,
FILE *outfile)
{
int ret;
/* send the frame to the encoder */
ret = avcodec_send_frame(enc_ctx, frame);
if (ret < 0) {
fprintf(stderr, "error sending a frame for encoding\n");
exit(1);
}
while (ret >= 0) {
ret = avcodec_receive_packet(enc_ctx, pkt);
if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF)
return;
else if (ret < 0) {
fprintf(stderr, "error during encoding\n");
exit(1);
}
printf("encoded frame %3"PRId64" (size=%5d)\n", pkt->pts, pkt->size);
fwrite(pkt->data, 1, pkt->size, outfile);
}
}
int main(int argc, char **argv)
{
const char *filename;
const AVCodec *codec;
AVCodecContext *c= NULL;
int i, ret, x, y;
FILE *f;
AVFrame *picture;
AVPacket *pkt;
uint8_t endcode[] = { 0, 0, 1, 0xb7 };
if (argc <= 1) {
fprintf(stderr, "Usage: %s <output file>\n", argv[0]);
exit(0);
}
filename = argv[1];
/* find the mpeg1video encoder */
if (!codec) {
fprintf(stderr, "codec not found\n");
exit(1);
}
picture = av_frame_alloc();
pkt = av_packet_alloc();
if (!pkt)
exit(1);
/* put sample parameters */
c->bit_rate = 400000;
/* resolution must be a multiple of two */
c->width = 352;
c->height = 288;
/* frames per second */
c->time_base = (AVRational){1, 25};
c->framerate = (AVRational){25, 1};
c->gop_size = 10; /* emit one intra frame every ten frames */
/* open it */
if (avcodec_open2(c, codec, NULL) < 0) {
fprintf(stderr, "could not open codec\n");
exit(1);
}
f = fopen(filename, "wb");
if (!f) {
fprintf(stderr, "could not open %s\n", filename);
exit(1);
}
picture->format = c->pix_fmt;
picture->width = c->width;
picture->height = c->height;
ret = av_frame_get_buffer(picture, 32);
if (ret < 0) {
fprintf(stderr, "could not alloc the frame data\n");
exit(1);
}
/* encode 1 second of video */
for(i=0;i<25;i++) {
fflush(stdout);
/* make sure the frame data is writable */
ret = av_frame_make_writable(picture);
if (ret < 0)
exit(1);
/* prepare a dummy image */
/* Y */
for(y=0;y<c->height;y++) {
for(x=0;x<c->width;x++) {
picture->data[0][y * picture->linesize[0] + x] = x + y + i * 3;
}
}
/* Cb and Cr */
for(y=0;y<c->height/2;y++) {
for(x=0;x<c->width/2;x++) {
picture->data[1][y * picture->linesize[1] + x] = 128 + y + i * 2;
picture->data[2][y * picture->linesize[2] + x] = 64 + x + i * 5;
}
}
picture->pts = i;
/* encode the image */
encode(c, picture, pkt, f);
}
/* flush the encoder */
encode(c, NULL, pkt, f);
/* add sequence end code to have a real MPEG file */
fwrite(endcode, 1, sizeof(endcode), f);
fclose(f);
av_frame_free(&picture);
return 0;
}